Used chemical containers found in a Waikato public reserve, initially seen as possibly linked to a clandestine methamphetamine lab, was a case of illegal dumping, police say.

A popular lakeside rest area off State Highway 1 at Karapiro was cordoned off today.

Police were called to the reserve shortly after 7.30am after members of the public made the discovery, district crime services co-ordinator Detective Senior Sergeant Nigel Keall said.

"Several empty chemical containers were found, along with glass jars and plastic tubs that had been used to hold acid," he said.

"Though we are still to establish just what it is we're dealing with, it was prudent to cordon off the area to await the arrival of Auckland-based forensic experts who will determine what, if any, further precautions need to be taken."

A forensic examination determined that the debris was illegally dumped chemical equipment but was not related the meth production.